11.3
Analysis techniques for boundary-layer atmospheric gravity waves
Carmen J. Nappo, CJN Research Meteorology, Knoxville, TN; and R. K. Newsom and R. M. Banta
It is accepted that gravity waves play an important role in the dynamics of the planetary boundary layer; however, the study of this role requires knowing the characteristics of the gravity waves, i.e. phase speed, direction, wavelength, frequency, and amplitude. These wave characteristics are usually derived from analyses of pressure data using, for example, band-passed filtering, spectral analyses, wavelet analysis, and beamsteering. Other analytical tools include phase averaging, lag analysis, and the so-called impedance relationship between wind speed and pressure perturbations. All of these techniques are based on the assumption of a monochromatic linear wave with constant amplitude which persists for many oscillations. In reality, this assumption is seldom, if ever, realized. Instead, one is often faced with a spectrum of waves of changing amplitude and frequency. As a result, large uncertainty often accompanies wave analyses. In this paper, several techniques for estimating wave characteristics are described and compared using several nights of data from the CASES-99 field experiment.
Session 11, Stable BLs - II
Thursday, 18 July 2002, 10:30 AM-12:30 PM
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